Supplement: Who Gets Immunotherapy for Cancer?

Improving Cancer Immunotherapy Success Rates

A successful response to cancer immunotherapy is only partly a matter of immune cell dynamics within a tumor. If a tumor is to be reduced and cleared, cancer immunotherapy must also engage systemic immunity.

For example, successful cancer immunotherapy can activate a population of peripheral memory immune cells. Cancer immunotherapy can also incorporate responses at the tumor site influenced by interactions between the gut microbiome and the immune system.

Cancer immunotherapy can be monitored through assays of protein biomarkers such as cytokines, chemokines, and growth factors. These biomarkers occur in blood samples, which may be obtained more easily and frequently than biopsy material. Biomarker signatures from the circulation may correlate with those from the tumor microenvironment. Also, blood-derived signatures may provide unique insights to overall response and efficacy.

“As demonstrated in durvalumab (anti-PD-L1) and nivolumab (anti-PD-1) clinical trials, such factors measured at baseline are more prognostic for overall survival than PD-L1 tissue staining,” he elaborates. “Frequent blood sampling and analysis during treatment allows for a comprehensive assessment of pharmacodynamic immunomodulatory activity. Recently, new ultrasensitive immunoassays that are capable of detecting low-abundance cytokines have been improving the utility of multiple blood-based proteins in immunotherapy development.”